Lacosamide [(R)-2-acetamido-N-benzyl-3-methoxypropionamide] of formula (I) is disclosed in U.S. RE 38,551. It shows effects in the treatment of pain, epilepsy, fibromyalgia syndrome, osteoarthritis and migraine.
The process for preparation of Lacosamide of formula (I) is disclosed in U.S. RE 38,551, WO 2006037574 and WO 2010052011.
The processes disclosed in these references are having following disadvantages:    a) Use of very expensive and hazardous reagents like silver oxide or butyllithium results in partial racemization which reduces the yield.    b) Purification with column chromatography techniques which is very difficult in commercial scale.    c) Use of expensive starting material.    d) Late stage optical resolution to afford high optical purity of Lacosamide.
In view of the preparation methods available for Lacosamide, there is a need for simple and cost effective process for the preparation of Lacosamide with high optical purity avoiding the use of expensive starting material and late stage optical resolution.